Articulated vehicles are known from the prior art. Thus rail vehicles that are connected to each other by way of an articulation are known, as well as e.g. articulated buses. In articulated buses, the bellows as part of the transition between the two vehicle parts of an articulated bus is relatively long because of the radiuses of the curves around which it must drive. In this respect, it is provided that the bellows is separated in the middle by a so-called central frame.
The transition not only comprises the bellows but also the bridge that is covered by the bellows in a rail vehicle or the platform in an articulated bus. As has already been explained, the box-shaped bellows encloses at least the transition bridge, though in an articulated bus not only the bridge but also the articulation. Between the transition bridge or the platform in an articulated bus and the side wall of the bellows there is usually a gap. For bridging this gap, a so-called floor-cover or track joint cover is known. Such a track joint cover is configured in an approximately trapezoidal shape in a lateral view and covers the track joint. Such a track joint cover is described for instance in EP 0 830 262 B1.
A split bellows is incidentally also known from this citation, the two bellows halves being separated by the central frame. The track joint cover also exhibits a corresponding separation in the area of the central frame of the bellows. This means that in the area of the central frame of the bellows, the track joint cover has a mounting frame that is configured in an approximately trapezoidal shape. At its end, the mounting frame is connected to the central frame of the bellows. In order to attach the mounting frame for the track joint cover, also called floor cover, the mounting frame comprises respective mounting blocks at each end, which are screwed to the mounting frame on the one hand and with the central frame on the other hand. Such a connection occurs on the central frame at both ends of the mounting frame. This means that the mounting frame is rigidly connected to the central frame. The mounting frame itself, which, in a lateral view, is configured in an approximately trapezoidal shape, consists of individual frame members, which are welded together.
A bellows of an articulated vehicle divided by a central frame is furthermore also known from EP 1741573 B1, the central frame however having a cross beam, which is disposed in the roof area of the central frame and which connects the two sides of the central frame in the area of the lateral wall of the bellows. The connection of the cross beam with the two sides of the central frame hereby occurs by way of brackets disposed on the central frame to which the cross beam is screwed or welded. This connection between the cross beam on the one hand and the central frame of the bellows on the other hand is also configured rigidly.
It is known that an articulated vehicle and here more specifically an articulated bus is exposed to various travel movements. For instance, such a vehicle is exposed to bending, pitching and rolling motions. Bending motions occur when the vehicle drives around a curve, while pitching motions occur when driving over a crest or through a hollow. Rolling motions are caused by a torsion-like twisting relative to each other of the two vehicle parts articulately connected to each other. Additionally, there are of course superimposed motions consisting of a combination of the afore-mentioned types of motion. The consequence is that the bellows must have considerable flexibility. This more specifically applies in the field of buses, since as has already been explained the articulated buses must be able to drive through partly very narrow curves. It has been determined that during superimposed motions, the coupling arrangements disposed on the central frame, namely the mounting frame on the one hand and the cross beam on the other hand strongly move relative to the central frame. Considerable tensions hereby occur in the area of the junction with the central frame, which frequently lead to a destruction of the connection. Furthermore, it must be noted that the buses of individual manufacturers are so different, that the coupling arrangements that have been described above, must be manufactured separately for each series of bellows, depending on the predominant geometrical relations on the central frame. This means that the known disposition of the coupling arrangements on the central frame of the bellows is not only at risk of being damaged but its manufacture and assembly is furthermore also relatively complex.
It has already been pointed out that the connection for receiving the cover surfaces shaped as expansion or concertina bellows for forming the track joint or floor cover in the area of the transition to the central frame occurs by screwing mounting blocks on the mounting frame in the area of the transition to the central frame. The mounting of the mounting frame on the central frame itself hereby occurs by way of screws inserted laterally into the mounting block and the central frame. The screws protrude from the central frame with their screw heads, the consequence being that the bellows rubs against the screw heads in this area, which leads to damage and eventually a destruction of the bellows.
It has furthermore been pointed out that the mounting frame consists of several frame members that are welded together in the shape of a trapeze trapezoid in order to form the mounting frame. The central frame as well as the mounting frame is manufactured with an aluminum alloy. Special suction devices are required when welding aluminum alloys, since the vapors that are produced during welding are harmful to health. The aluminum dusts that are subsequently produced during cleaning must also be sucked away due to the explosion hazard. Such a welded connection is furthermore rigid, the consequence being that, just as with the rigid junction of the mounting frame to the central frame of the bellows, fractures are formed in the mounting frame, here more specifically in the area of the welds.